The invention relates to intraocular lenses particularly suited for anterior-chamber implantation in the human eye, relying solely upon anterior-chamber features for stabilized optically correct location.
Prior lenses of the character indicated are exemplified by those disclosed in Choyce, et al., U.S. Pat. No. 4,087,866, in Bayers U.S. Pat. No. 4,134,161, and in the technical paper entitled "Surgical Complications of Choyce-Type Implants", by R. H. Keates, et al., presented at the 1978 Annual Meeting of the American Academy of Ophthalmology, Symposium on Intraocular Lenses. As far as I am aware, all such prior lenses have been of plastic construction, and they are tissue-reactive, in the sense that tissue growth is not retarded and can become a clouding factor to degrade optical performance of the implant. With present lenses, sterilization must be accomplished using a caustic solution or ethylene oxide gas*. Such lenses are injection-molded products and therefore cannot be classed with the quality of an optically finished glass lens. But glass lenses as implants have been generally shunned, primarily because of the high specific gravity of glass, as compared to that of plastic; see Binkhorst, et al., "A Weightless Iseikonic Intraocular Lens", American Journal of Ophthalmology, Vol. 58, No. 1, July 1964, pp. 73 to 78. And, in particular, it is noted that although Choyce, et al. U.S. Pat. No. 4,087,866 mentions glass as a possible lens material, the disclosure is silent on any suggestion of optically finished glass for the purpose. FNT *A glass anterior chamber lens would allow for autoclaving.